It has been estimated that at least 10-15% of the elderly American population, or 2-3 million individuals, experience impairments in more than one sensory modality, including hearing, sight and touch. The proposed project assesses the performance of a large group of young and elderly adults on a battery of tests that measure temporal-processing abilities in the auditory, visual and tactual senses. The primary aims of the proposed project are: (1) to determine whether temporal processing of sensory input by adults is affected by advancing age in either the auditory, visual or tactile modalities; (2) to establish whether correlations exist across sensor modalities for similar measures of temporal processing obtained from the same set of young and elderl, participants; and (3) to determine whether various measures of temporal processing within a particular modality are correlated, regardless of age. The first aim is addressed primarily through examination of differences in performance on auditory, visual and tactile measures of temporal processing between groups comprised of the same set of young and elderly individuals, as well as through correlations with age. Based on isolated experiments on temporal processing conducted previously within each sensory modality, it is anticipated that elderly subjects, as a group, will perform worse than young adults on most of these tasks and will likely do sc for each modality. Since a parallel set of temporal measures will be obtained across all three modalities however, the proposed project also will be able to address the aims identified above through correlational analyses. In addition, regarding the second aim, within a given age group, correlations in performance across modalities on a particular temporal-processing measure will provide strong evidence that such processing is amodal, likely sharing a common underlying central or cognitive process. In this way, use of young and elderly subjects in the proposed project will not only shed light on the nature of sensory impairments experienced b the elderly, but also on the nature of temporal processing mechanisms across modalities regardless of age. Structural equation modeling will be used to examine the correlations between measures and address the degree to which different modalities share a common temporal processing mechanism that is affected by age.